Vacancy-driven ferromagnetism in ferroelectric PbTiO₃

Abstract

The possible origin of ferromagnetism in PbTiO 3 containing vacancies is investigated by performing first-principles calculations. We demonstrate that O and Ti vacancies both induce ferromagnetism but by different mechanisms: the ferromagnetism driven by the O vacancy originates from the spin-polarized e g state of the nearest Ti atom, whereas that driven by the Ti vacancy is due to the half-metallic p x state of the nearest O atom. The results presented here provide fundamental insights into the design of multiferroics in conventional ferroelectrics.

Physical Properties of Sol-Gel Lead Nickel Titanate Powder Pb(Ti_1&minus;<i>_x</i>Ni<i>_x</i>)O₃

“…4) The existence of a weak ferromagnetic order in pure phase PbTiO 3 can be assigned to the oxygen vacancy which causes a very small saturation magnetization about of 0.0006 emu/g. 11,12) All PbTi 1¹x Ni x O 3 samples exhibit the S-type M-H curves of ferromagnetism with the gradually increase of both coercive force H C and saturation magnetization M S with increasing Ni content. For Ni12 sample, the values of saturation magnetization M S and coercive field H C reach to 0.0056 emu/g and 705 Oe, respectively.…”

“…In addition, many theoretic calculations on doped and un-doped PbTiO 3 were carried out to interpret the origin of the variation in ferroelectric as well as ferromagnetic orders in this single phase magnetoelectric material. 11,12) . Ethylene glycol was then added into this sol as a surfactant.…”

Ferromagnetism in ferroelectric BaTiO3 induced by vacancies: Sensitive dependence on charge state, origin of magnetism, and temperature range of existence

“…It may be worth pointing out that, although studies on magnetism in another material PbTiO 3 exist, [55][56][57] the results of PbTiO 3 , however, cannot be directly applied to BaTiO 3 , due to rather drastic differences between two materials. In PbTiO 3 , there are strong Pb-O hybridization, large c/a ratio, dissimilar Ti-O bonds (all of which do not exist in BaTiO 3 ).…”

Band gap narrowing and magnetic properties of transition‐metal‐doped Ba0.85Ca0.15Ti0.9Zr0.1O3 lead‐free ceramics

“…Perovskite ferroelectric materials have received increasing research attention owing to their promising electrical, mechanical, thermal, magnetic, optical, and other properties . Traditional lead‐based perovskite materials, such as PbTiO 3 (PTO) and PbZr x Ti 1− x O 3 (PZT), are well known for their outstanding electrical properties, but also arouse great concerns as their excessive lead content causes significant harm to the human body and environment. Consequently, the development and utilization of lead‐free materials have been promoted .…”